436 Steps to Sustainable Ruminant Livestock Production – the role of instrumented farms and networks.

摘要

Global agriculture is at a critical juncture where competing requirements for maximal production and minimal pollution impose various patterns of economic-environmental trade-offs. Livestock production is central to this debate, as it is estimated to generate 7.1 Gt CO2-e of greenhouse gases (GHG) each year, and to occupy 30% of the Earth’s surface, of which one-fifth is subject to land degradation due to inappropriate management and overproduction. These statistics, together with the notion that cereals and pulses currently being fed to livestock could potentially be consumed by humans to alleviate hunger, have frequently led to a criticism that livestock farming is an unethical industry.On the other hand, ruminants can utilise land unsuitable for arable crop production and convert fibre and low quality nitrogen sources to nutritionally-valuable human-edible protein. Furthermore, grazing animals have been shown to be net providers of a range of ecosystem services and, depending on the natural conditions, capable of not only maintaining but also regenerating soil fertility by facilitating nutrient cycling.Using high-resolution primary data from an intensively instrumented farm-scale ruminant research facility located in southwest UK a novel, information-driven approach to carry out comprehensive assessments of economic-environmental trade-offs inherent within pasture-based production systems is proposed. The results suggest that a potentially systematic interaction exists between ‘soil health’, ecological surroundings and livestock grazing, whereby a higher level of soil organic carbon (SOC) stock is associated with a better animal performance and less nutrient losses into watercourses, and a higher stocking density with greater botanical diversity and elevated SOC. We contend that a combination of farming system-wide trials and environmental instrumentation provides an ideal setting for enrolling scientifically sound and biologically informative metrics for agricultural sustainability, through which agricultural producers could obtain guidance to manage soils, water, pasture and livestock in an economically and environmentally acceptable manner.